Locking device for telescoping members



Jan. 16, 1945. s E BUTLER 2,367,196 I LOCKING DEVICE FOR TELESCOPING MEMBERS Filed Oct. 15, 1943 2 Sheets-Sheet 1 IN V EN TOR. SET/l fbGE/VC BUTL 5/? BY A TTORN:

Jan. 16, 1945. s.'E. BUTLER 2,357,195

LOCKING DEVICE FOR TELESCOPING MEMBERS Filed Oct. 15, 1945 2 Sheets-Sheet 2* .IN VEN TOR. 557 fl/GfNf 5072f? A TTORNEY Patented Jan. 16, 1945 LOCKING DEVICE FOR TELESCQPING MEMBERS Seth E. Butler, Union City, N. J., assignor to Federal Telephone and Radio Corporation, New I York, N. Y., a corporation of Delaware Application October 15, 1948, Serial No. 506,437

11 Claims.

The present invention relates to locking means for telescoping members.

In numerous arrangements in which telescoping members are utilized, such for example as antennas or adjustable supports such as tripods and the like, it is desirable, after a certain relative position or setting of the members has been reached, to lock the members so that further telescopic movement may be prevented.

The devices now used for accomplishing this result are often complex, bulky, or else fail to give a positive locking action at all times. Furthermore, those employing parts located on the outer surface of one or both telescopic members are unsuited for certain uses such as in antenna structures where radiation would be seriously interfered with.

One object of the present invention, therefore, is to provide a locking device for telescopic members which is simple in design, positive in action, and relatively inexpensive to manufacture.

A further object of the invention is to provide a locking device for telescopic members which is entirely self-contained, that is, all theparts of the device being located within one of the telescopic members.

A still further object of the invention is to provide a locking mechanism for telescopic members which may be operated to locking position by a small angular rotation of either member relative to the other, and which may be returned to unlocked position by a reverse rotation of the same magnitude.

. An additional object of the invention is to provde an expansible sleeve carried by one of two telescoping members and to provide camming means for expanding this sleeve upon a selective relative'rotation of the members.

Other objects and advantages will be apparent from the following description of preferred forms of the invention and from the drawings, in which:

Fig. 1 is a plan view of an adjustable antenna rod incorporating a preferred form of locking device in accordance with the present invention;

Fig. 2 is an enlarged sectional view along 22 of Fig. l;

Fig. 3 is an exploded perspective view of a porton of Fig. 2;

Fig. 4 is 'a sectionalview of a modified form of the invention illustrated in Figs. 1 tln'ough 3.

In the embodiment of the invention illustrated in Figs. 1 through 3 is shown a pair of tubular members 6, 8 arranged in telescoping relation,

closed within the former.

flanged portion it of extended diameter as shown in Fig. 2, this flanged portion facilitating set- 1 ting of the collar within member 8 and also providing a suitable stop action against the spun over end N5 of member 6 so as to prevent separation of the two tubular members.

Collar I'll is designed to threadably receive a spindle l2 having a threaded surface portion I8. This threaded surface portion l8 of spindle l2 projects beyond the end of tubular member 8 and on the far end of this spindle is formed a ball-shaped head or knob 20. The spindle is held against rotation within the collar by some suitable method such as soldering. When assembled, the tubular member 8, the collar I0, and the spindle l2 constitute a unit in which there is no relative movement of the parts.

A sleeve or nut 22 having an end portion 32 is provided with an internally threaded bore 24 engaging the outer threaded surface l8 of spindle l2, and this sleeve issplit diametrically as best shown in Fig. 3 into two segments 22a.and

22b. Sleeve 22 is proportioned so that the outer cylindrical surface thereof engages the inner surface of tubular member 6 as indicated at 36. This engagement. is in the form of a normally slidable frictional relationship of these surfaces with respect to a relative axial movement of the the latter member being normally partially entwo tubular members 6 and 8, and in the form of a normally non-slidable frictional relationship of the surfaces with respect to a relative rotary movement of the tubular members. In other words contact surfaces 36 normally permit the sleeve 22 to be slid longitudinally within member 6, but will not normally permit sleeve 22, to be rotated with respect to member 6. Therefore, any relative rotation of members 8 and 8 will produce a corresponding relative rotation of sleeve 22 and spindle l2, and since these members are in threadable engagement the sleeve will travel along the spindle.

With the sleeve 22 in'its normal longitudinally spaced apart position from head 20, a rotation of either tubular member 6 or 8 relative to the other contact with respect to a. relative rotary movement of the tubular members. Upon a selective relative rotation of members 6 and 8', surface portions 4|, 44 will be brought into engagement, and

tation of members 6, 8 maybe chosen so that the sleeve will traveltoward, and finally engage, head of the spindle.

The bore of sleeve 22 has a beveled edge 38. Engagement between the ball-shaped head 20 of spindle l2 and this beveled edge 38 will result in a camming action of the head against the sleeve. and the segments 22a and 22b will be spread apart or expanded radially outward against the inner surface of tubular member 6. The outward expension of segments 22a and 22b will terminate the normally slidable frictional relationship ofsurfaces 36 of the sleeve axially of tubular member 8, and the sleeve, together with the other tubular member 8, will be locked in place against any longitudinal movement relative to member 6 until such time as a reverse relative rotation of the members releases sleeve 22 from its engagement with head 20 and unlocks the mechanism.

It will noted that only a very small relative angular rotation of the members 6, 8 is required to either lock or unlock the mechanism, although the amount of rotation obviously depends on the camming angle between head 20 and beveled edge 38 of sleeve 22, and also on the number of threads per inch of spindle l8.

To prevent the end portion 32 of sleeve 22 from becoming wedged or jammed within collar ID, a shoulder on sleeve 22 is provided so as to contact shoulder II on colla In prior to such time as engagement between the collar and portion 32 would otherwise be made. Due to the fiat surface contact of shoulders 80 and N, no jamming between sleeve 22 and collar II] can occur.

Inasmuch. as a removal of inner member 8 from outer member 6 for inspection of the locking split sleeve 22 is provided to hold the segments together.

the split sleeve 42 will be spread radially outward or expanded against the inner surface of tube 8' to terminate the normally slidable frictional engagement of the sleeve axially of tubular member 6 to thereby lock the members 6 and 8' in position against relative longitudinal movement.

It should 'be noted that in the modification of Fig. 4 it is possible to construct the member 8 as a hollow tube having an unobstructed junction with tube 6. This permits the telescoping mem bers to be utilized in situations where a closed or blocked passageway through the members could not be employed.

While 1' have described above the principles of my invention in connection with a specific mechanism, and particular modifications thereof, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention as set forth in the objects of my invention and the accompanying claims.

I claim:

1 The combination of two tubular members in telescoping relation, said members being capable of relative rotary movement, caimning means rigidly secured to the inner of said members, radially expansible mean carried by said inner member in normally longitudinally spaced apart relation from said cumming means, and means responsive to a selective relative rotary move ment of said members for bringing said camming means into contact with said expansible means,

An annular recess :4 may be cut intdsleeve 22 primarily to reduce the weight of the sleeve. However if desired the sleeve may be formed to omit this cut-out portion 34.

In Fig. 4 is shown a modification of the looking device of Figs. 1 through 3. 'In this modification the enclosed end of inner member 8' is flared outwardly as shown at 40, thereby forming a frustro-conical surface portion 4!. A split sleeve 2 having an internally threaded bore 48 isheld together by a retaining ring 43 having an action similar to the retaining ring 26 in the device shown in Figs. 1 through 3. Split sleeve" also has a frustro-conical surface portion Q4 designed for engagement with the surface portion ll of flared end 40. A section of the outer surface of whereby the latter will be ex nded radially by said camming means against the outer of said members.

2. The combination of claim 1 wherein said expansible means is formed with a threaded bore. and wherein said means for bringing said camming means into contact with said expansible means includes a threaded spindle engaging said threaded bore.

ried by said first member in normally longituditubular member 8 is threaded as shown at 48 to engage the threaded bore 48 of sleeve 42.

The principle-of operation of the device of Fig. 4 is similar in several respects to that of the mechanism of Figs. 1 through 3. The surface portion 44 of split sleeve 42 is normally spaced apart nally spaced apart relation from said camming means, and in contact with the second of said members, said expansible means and the second of said members being in normally slidable frictional engagement with respect to a relative ax,- ial movement of said members,'and in normally non-slidable frictional engagement with respect to a relative rotary movement of said members, and further means responsive to a selective relative rotary movement of said members for bringing into engagement said camming means and said expansible means, whereby the latter will be expanded radially by said camming means against the second of said members.

4. In a locking device, a first hollow tubular member, a second tubular member arranged in telescoping relation within said first member, a I

threaded spindle secured to and projecting axially beyond one end of said second member, said spindle being enclosed within said first member; camming mean carried by the projecting end of said spindle, a split nut threadably engaging said spindle, and means responsive to a selective relative rotation of said members for causing said nut to travel along said spindle and into engagement with said camming means, whereby said nut will be spread apart by said camming means and forced against the inner ed outer surface portion adjacent the enclosed end thereof, said enclosed end being flared outwardly, comprising a split nut encircling said inner member, normally longitudinally spaced from the flared end thereof, and threadably engaging said threaded portion, said nut being normally in frictional contact with said outer member, whereby. said nut will engage and be expanded by the flared end of said inner member .upon a selective relative rotation of said members.

members in normally slidable contacting rela- .7

tion longitudinally of the outer of said members,

and means rigidly secured to the inner of said members in normally spaced apart relation longitudinally of said first-mentioned means and operative upon a selective rotation of either member with respect to the other for radially expanding said first-mentioned means against said outer member to thereby terminate the slidable contacting relation of said first-men- 10. In combination, a first tubular member, a second tubular member enclosed at least partly in telescoping relation within said first mentioned member, the enclosed end of said second tubular member being formed with a sloping outer surface portion of extended diameter, said second member being threaded on that portion of its outer surface adjacent said sloping end portion, and an outwardly expansible nut threadably engaging said outer threaded surface of said second member, normally free of said sloping portion, and in slidable frictional engagement axially of said first member, whereby a selective relative rotation of said tubular members will cause said nut to contact said sloping portion to be thereby expanded outwardly tioned means longitudinally of said outer member. a v i 'I. A locking mechanism for a. pair of tubular members arranged in telescoping relation comprising a threaded spindle secured to and pro jecting axially beyond one end of the inner of said members, said spindle being enclosed within the outer of said members, a knob formed on the projecting end of said spindle, and a split nut threadably engaging said spindle and frictionally engaging said outer member, said nut and said spindle beingdesigned for axial movement relative to one another upon a selective relative rotation of said members without dis-- turbing the frictional engagement between said nut and said outer member.

8. A locking mechanism as defined in claim 7 in which said split nut is formed with an annular groove, in combination with a retaining ring in said groove.

9. .Mechanism for locking together two hollow tubular members positioned in telescoping relation, the inner of said members having a thread.-

against said first member to thereby terminate the said slidablefrictional engagement of said nut axially of said first member.

11. An adjustable antenna rod comprising a pair of rotatable tubular members arranged in telescoping -relation, and mechanism for temporarily locking together said tubular members so as to preclude telescopic operation, said mechanism including radially expansible means carried by the inner of said tubular members, said expansible means being in frictional contact with the outer of said members and in normally slidable engagement longitudinally-thereof, and means rigidly secured to the inner of said members in normally longitudinal spaced apart relation from said expansible means and operative upon a selective relative rotation of said tubu- I lar members for radially expanding said expansible means against said outer member to terminate the slidable engagement of said expansible means longitudinally of said outer member.

saw a BUTLER. 

